"It's tough. It's very, very tough but if you have good friends and family support [you can get through it]," he said on Good Morning America. "It's a horrible situation but time hopefully will heal. It's a reality of life."

And being able to throw himself into work, Stallone is currently promoting The Expendables 2 with good friends Arnold Schwarzenegger and Bruce Willis, is helping the actor adjust to life without Sage. "It's important to get back and try to start reliving your life or you can go into a spiral."

Sage, who made his movie debut alongside his father in Rocky V, was one of two sons from Stallone's first marriage to Sasha Czack.